siemens. answers. lookin' good, flo! feelin' good! feelin' real good! [ engine revs ] boat protection people love. now, that's progressive. call or click today. >>> when is a d plus a good grade? when it's better than the grade you got four years ago. this isn't a term paper. these are america's roads, bridges, waterways and power lines. this d plus is the first time in 12 years that america's infrastructure has earned a grade this high. a new report out this week from the american society of civil engineers measures 16 categories from aviation to roads and waste water. no category earned a lower grade than it did four years ago. six categories saw improvements. bridges, railroads, drinking water, solid waste, and drinking water. solid waste earned the highest grade on the report, a b minus. go solid waste. what's driving the improvements? the stimulus gave infrastructure a short-term boost. cities and states are renewing their efforts to fix roads, bridges, drinking water and waste water systems and private companies are investing in railways, ports, a